'Classroom obesity checks may damage children' say experts

National weight testing in schools will not benefit fat pupils and may even harm them, claim researchers.

The Government last year introduced classroom obesity checks for youngsters in a bid to tackle the nation's growing weight crisis.

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But there is a lack of evidence that screening will drive down obesity in the long-term and it might even be damaging, says a new report in the journal Archives of Disease in Childhood.

It says the best approach is to allow children with weight problems to seek help themselves rather than be identified as part of a national programme.

The first round of national weight testing last year was regarded by some as a costly flop because thousands of parents refused to give consent for their children to be screened.

Ministers wanted all pupils to be weighed and measured at ages four and ten, but fewer than half the target children submitted to the checks.

Fears that overweight children will be bullied are thought to be the reason why some parents to refuse permission for school nurses to weigh their children.

The number of fat children has doubled in 10 years with one in four children aged 11-15 years now classified as obese - so fat it threatens their health - with almost half of girls obese or overweight.

The Government is widely expected to miss its target to halt the rise in childhood obesity among under-11s by 2010.

A review of studies on the impact of weighing children has found there is little evidence that preventative approaches or current treatments actually drive down children's obesity.

Dr Marie Westwood, who led researchers at the Centre for Reviews and Dissemination at the University of York, said monitoring weight was useful for gathering information on obesity and identifying how money should be spent.

It could also provide data on the impact of school initiatives to improve children's diets and lifestyles, and may be useful in tracking individual children into adulthood.

But evidence on whether treatments work is "doubtful" and no-one knows if screening is harmful, claims the report.

It says: "The value of moving from population monitoring to screening to identify and treat individual children remains at best questionable.

"The effectiveness of treatment is currently doubtful and the potential harms of either monitoring or screening are poorly researched.

"In the light of this, current models of self-referral appear the best basis for attempts to treat obesity and should continue."

But Tam Fry, board member of the National Obesity Forum, said weighing and measuring children in schools was "absolutely appropriate".

The measurements are used to calculate children's Body Mass Index, (BMI) scores that relate weight to height.

Adults with a BMI score of between 25 and 30 are classified as overweight, while a score of 30 and over is obese.

Children with BMI scores in the top five per cent compared with others of the same age and sex are also described as obese.

Mr Fry said few studies had been carried out on the effectiveness of interventions and more were needed.

"It's high time now we actually properly started to measure height, weight and BMI in order to pick up early signs of problems developing and do something about it" he added.

Last year's survey suggested that 22.8 per cent of five year-olds and 31.1 per cent of 11-year-olds are overweight or obese, with boys fatter than girls at both ages.

But these figures relate to measurements taken from only 48 per cent of the intended sample of more than a million children, with heavier children more likely to opt out.

The figures "are likely systematically to underestimate the prevalence of childhood obesity", it was claimed.